1. Field of the Invention
The present invention relates to alternating esteramide polymers, and more particularly, to polyesteramides derived from bis-oxamidodiols and dicarboxylic acids or their diesters.
2. Description of Prior Art
Polyesters and polyamides are well-known thermoplastic heterochain polymers, and polyesteramides have been studied as a hybrid of these two basic polymers. U.S. Pat. No. 3,493,544, for example, describes the preparation of a random polyesteramide copolymer by reacting diamines and diacids in the presence of a lactone. U.S. Pat. No. 3,493,632 discloses the preparation of block polyesteramides by heating a mixture of a polyester and a polyamide to a temperature intermediate the glass transition temperatures and melting temperatures of the two polymers.
Other reports in the literature disclose the preparation of polyesteramides by reacting a bis-esteramide and a diol [Europ. Polym. J. 12, 585 (1976), Polymer 16, 565 (1975)], a diamidediol with a dicarboxylic acid [J. Appl. Polym. Sci. 20, 975 (1976)], an .omega.-aminoalcohol or aminophenol with a diacid [Bull Soc. Chim. (France), 2264 (1971), French Pat. No. 2,016,340], an ethanolamine with an oxalic ester [J. Agr. Chem. Soc., Japan 18, 54, 76 (1942); Chem. Abs. 45, 2214g, 2215a (1951)], and an aminoisopropanol with oxalic acid [J. Agr. Chem. Soc., Japan 19, 805 (1943); Chem. Abs. 45, 8777e (1951)].
Bis-amide diols derived from C.sub.2 to C.sub.4 aminoalcohols have also been disclosed in the art [J. Chem. Soc., 2006-10 (1956); Chem. Abs. 51, 263d (1957), Plaste u. Kautschuk 6, 372-75 (1959); Chem. Abs. 54, 6180e (1960)]. None of the prior art references, however, disclose the reaction of bis-oxamidodiols with dicarboxylic acids to obtain the novel polyesteramides of the present invention.
It is accordingly an object of the present invention to provide new, alternating polyesteramides derived from the reaction of bis-oxamidodiols with a dicarboxylic acid or diester. It is a yet further object of this invention to provide new polyesteramides which are susceptible to hydrolysis and useful in the preparation of absorbable sutures and other surgical devices. Another object of this invention is to provide hydrolytically stable, fiber-forming polyesteramide polymers useful in the preparation of nonabsorbable surgical sutures and textile fibers. These and other objects of the invention will be apparent from the ensuing description and claims.